"Saying, 'Sir' helps. Hands visible helps. Even if you've got a Ph.D. from Harvard," he added. "It's about survival. I describe it as ... making him feel at that time he's in charge."

New Yorker Eric Garner died this summer after a police officer put him in a chokehold while stopping to arrest him for allegedly selling "loosie" cigarettes. About a month later in Ferguson, Missouri, a police officer shot and killed 18-year-old Michael Brown after a physical struggle. And last month, a Cleveland cop fatally shot a 12-year-old boy who was playing with a fake gun.

Roland Nicholson

Roland Nicholson in an undated photo with two of his sons.

While each case is different, there is one constant that has captivated the nation, sparking protests about police brutality and race across the country: the victim was black and unarmed, and the police officer is white.

"This is not Mississippi in 1960, but something is still not right," Nicholson said. "You look at some corner offices -- you look at the Oval office -- and you think, we've moved past a lot of things. And we just haven't."

Nicholson's youngest son is now 18 -- the same age as Michael Brown -- and drives a BMW.

"Because he is so young, he does get pulled over," he said. "I tell him, 'You don't have to put your hands up and say don't shoot, but you do need to make it clear to him [the police officer] that they're visible."

He said his sons had questions when they learned that the officer who shot Tamir Rice, the 12-year-old Cleveland boy, had records of emotional maturity issues and "dismal" performance in firearms training, according to the personnel file released by his former employer.

"They [his sons] said, 'How did he get that job?' I said that's a slip-up in the system that we have to be prepared for," Nicholson said.

Tanya Cain, an African-American mom in New Jersey, told ABC News she also struggles with what to say to her 12-year-old son, who's the same age as Tamir Rice.

She recalled telling him to pull down his hood while they were at the mall shopping, and making him change when he was heading to basketball practice in a plain white T-shirt.

"The white T-shirt was no big deal to him, but it was a big deal to me," Cain said. "It's another conversation: You're never going to walk out of the house with a plain undershirt like that.
“There's a perception of young black kids who walk around with baggy jeans and a white T-shirt, an undershirt. There's a negative connotation. And we don't want to project that, whether it's fair or not. So I made him go upstairs and change."

Mireya Acierto/Getty Images

New York City Mayor, Bill de Blasio and son Dante de Blasio attend Celebrate Brooklyn! Opening Night Gala And Janelle Monae Concert at Prospect Park Bandshell, June 4, 2014 in New York.

Tiersa McQueen of Plano, Texas, told ABC News she hopes her three black sons are too young to have to worry about police interactions, but she's fearful for when they're older.

"My husband and I feel it's important to educate our children on how to handle themselves when they are confronted by police officers," she said. "The best thing you can do is just avoid police altercations in the first place.

"I can't take the black skin off of them."

Even New York City Mayor Bill de Blasio has said he struggles with how to tell his biracial son Dante to deal with police.

"What parents have done for decades who have children of color, especially young men of color, is train them to be very careful when they have a connection with a police officer," de Blasio said on ABC's "This Week" with George Stephanopoulos.

"It's different for a white child," de Blasio said. "That's just the reality in this country. And with Dante, very early on with my son, we said, look, if a police officer stops you, do everything he tells you to do, don't move suddenly, don't reach for your cellphone, because we knew, sadly, there's a greater chance it might be misinterpreted if it was a young man of color."

The mayor also brought up his son at an earlier press conference where he discussed a new training program to reform the NYPD. Those comments angered police union leaders.

"What police officers felt yesterday after that press conference is that they were thrown under the bus," said Patrick Lynch, the head of the Patrolmen's Benevolent Association, according to The Associated Press. "If the mayor wants to change policies, and wants us to stand down against crime, then say that."